3 Citing your sources

 One of the goals for any class is to help students become better scholars. And, one of the important skills of scholarship is proper citation of resources used. Citations demonstrate your “credentials” as a scholar, and provide a resource to your readers of good reference material. This section of the textbook contains basic information about citing sources. For more information, see your course materials or ask your instructor.

Why do you have to cite your sources?

No research paper is complete without a list of the sources that you used in your writing.  Scholars are very careful to keep accurate records of the resources they’ve used, and of the ideas and concepts they’ve quoted or used from others. This record keeping is generally presented in the form of citations.

A citation is a description of a book, article, URL, etc. that provides enough information so that others can locate the source you used themselves. It allows you to credit the authors of the sources you use and clarify which ideas belong to you and which belong to other sources. And providing a citation or reference will allow others to find and use these sources as well.  Most research papers have a list of citations or cited references and there are special formatting guidelines for different types of research.

However, there are many “proper” formats because each discipline has its own rules. In general we ask only that you use one of the “official” formats and that you use it consistently. To understand what we mean by “consistent”, compare the citations in two scientific journals. You will notice that each journal has its own rules for whether an article title is in quotes, bold, underlined, etc., but within each journal the rule applies to all reference citations. Below is a condensed guide to the general format used in science (CSE). For more detailed information consult one of the online citation guides and generators.


Plagiarism is presenting the words or ideas of someone else as your own without proper acknowledgment of the source. When you work on a research paper you will probably find supporting material for your paper from works by others. It’s okay to quote people and use their ideas, but you do need to correctly credit them. Even when you summarize or paraphrase information found in books, articles, or Web pages, you must acknowledge the original author. To avoid plagiarism, include a reference to any material you use that provides a fact not commonly known, or whenever you use information from another author.  In short, if you didn’t collect the data or reach the conclusion on your own, cite it!

These are all examples of plagiarism:

  • Buying or using a term paper written by someone else.
  • Cutting and pasting passages from the Web, a book, or an article and insert them into your paper without citing them. Warning! It is now easy for your instructors to search and identify passages that you have copied from the Web.
  • Using the words or ideas of another person without citing them.
  • Paraphrasing that person’s words without citing them.


Tips for Avoiding Plagiarism:

  • First, use your own ideas—it should be your paper and your ideas should be the focus.
  • Use the ideas of others sparingly—only to support or reinforce your own argument.
  • When taking notes, include complete citation information for each item you use.
  • Use quotation marks when directly stating another person’s words. Quotes are not frequently used in scientific writing unless you are directly quoting someone’s spoken words.

Citing Sources in APA Format

There are a number of different citation formats that are commonly used in scientific writing. CSE format emphasizes who wrote the information and when they wrote it. In different fields, there is an emphasis on different types of information. In the humanities, MLA format is commonly used. This style emphasizes the author’s name and the page number. This information allows a reader to track down the exact quotes that are being discussed. The format that we will be using in this class, APA, emphasizes the author’s name and the year the information was published.

The standard format for citing a source in science writing is the Name-year format. In this format, the first author’s last name is followed by the date. For example:  Not all populations of alligators in the everglades are at risk from habitat loss (Nicholson, 2002).

Beware of computerized “citation creators.”  While they can get you part way to a correct citation, they rarely are 100% correct.  For example, they often fail to put the last name first.

Citing a scientific journal article

Basic Format: Lastname, F. M., Author2, B. B., & Author3, C. C. (Year). Title of article. Title of Periodical, volume number(issue number), pages.

Please note that you need to cite the JOURNAL, not the DATABASE that you got it from. Citing the database in which you found a scientific journal article is like citing Google for an internet resource that you are using. If you accessed the journal through the library database, do not cite the database!


Flores-Cruz, Z. & Allen, C. (2011). Necessity of OxyR for the hydrogen peroxide stress response and full virulence in Ralstonia solanacearum. Appl Environ Microbiol. 77(18):6426-6432.

Werling, B.P., Lowenstein, D.M., Straub, C.S., Gratton, C. (2012). Multi-predator effects produced by functionally distinct species vary with prey density. J Insect Sci; 12(30): 346-378.

Shriner, W.M. (1998). Yellow-bellied marmot and golden-mantled ground squirrel responses to heterospecific alarm calls. Animal Behaviour 55:529-536.

Citing an internet resource

Basic Format: Lastname, F. M. (Year, Month Date). Title of page. Site name. URL

Schneegans, S. (2021). Tis the Season… For Leaf Gall. Knecht’s Nursery and Landscaping. https://knechts.net/tis-the-season-for-leaf-gall/

[BP] The Biology Project. (2003). The chemistry of amino acids. University of Arizona. http://www.biology.arizona.edu/biochemistry/problem_sets/aa/aa.html

Hilton-Taylor C, compiler. (2000). 2000 IUCN red list of threatened species. Gland (Switzerland) and Cambridge (UK): IUCN. http://www.redlist.org/.

  • What if there’s no author listed? You can assume that the article was written by staff of the organization that published the article. If the article was written by an organization and not a specific author, you can use the name of the organization (or an abbreviation for the name).
    • Sickle cell anemia is caused by abnormally-shaped haemoglobin proteins (NHLBI, 2020).
    • [NHLBI] National Heart Lung and Blood Institute. (2020). Sickle Cell Disease. National Institutes of Health. https://www.nhlbi.nih.gov/health-topics/sickle-cell-disease
  • What if the name of the organization is really long? As seen in the example above, you can use an abbreviation for the name of the organization (preferably the abbreviation that the organization itself uses). You place this abbreviation in square brackets at the very beginning of the citation. You can use this abbreviation in your in-text citation.
  • What if there’s no date of publication? If you can find a copyright date (often at the very bottom of the webpage), you can use that. Put a c in front of the date (example: c2020). If there’s no date given at all, you can use the abbreviation (n.d.) for “not dated”.

In the Reference List section (a.k.a. Literature Cited or Works Cited…) list all the sources you cited in your paper, but do not include any items that you did not specifically cite within the body of your paper or project, even if you read them!  Except in rare instances, do not cite a reference that you have not personally read.

All of the references in the Reference List section should be listed alphabetically by author’s last name. That doesn’t mean that you alphabetize the authors within one reference! Always leave author’s names in the order that they are given – in scientific publications, the order of the authors is very important.


“Cite Your Sources” by University of California, Santa Cruz, University Library is licensed under CC BY 3.0

“What is plagiarism?” by University of California, Santa Cruz, University Library is licensed under CC BY 3.0


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Mt Hood Community College Biology 101 Copyright © 2016 by Lisa Bartee and Christine Anderson is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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